Positioned in the Southwest corner of Puerto Rico, the Cabo Rojo salt flats are the single most important converging point for migrating shorebirds in the eastern Caribbean.

In total, 25 species of shorebirds have been recorded from the salt flats.

During the winter, spring and summer, the Cabo Rojo salt flats are prime nesting habitat for killdeers, black-necked stilts, Wilson's plover and the locally threatened snowy plovers which occur nowhere else in Puerto Rico.

In addition to shorebirds, numerous resident and migratory birds make use of the area. At least 28 water dependent species and 65 land-dwelling species use the lagoons and surrounding vegetation. Among the most common species are those directly dependent on the availability of aquatic habitat.

The Salt Flats also lie within designated critical habitat of the yellow-shouldered blackbird, a Federally-listed endangered species.

Yellow-shouldered blackbirds use the upland and wetland vegetation surrounding the salt flats as corridors between feeding and roosting areas and opportunely as feeding areas.